A switched-mode power converter (also referred to as a “power converter” or “regulator”) is a power supply or power processing circuit that converts an input voltage waveform into a specified output voltage waveform. DC-DC power converters convert a direct current (“dc”) input voltage into a dc output voltage. Controllers associated with the power converters manage an operation thereof by controlling the conduction periods of power switches employed therein. Generally, the controllers are coupled between an input and output of the power converter in a feedback loop configuration (also referred to as a “control loop” or “closed control loop”).
To produce a dc output voltage, power converters employ magnetic devices such as inductors and transformers. A high-frequency alternating current (“ac”) voltage is applied to a winding of the magnetic device that is typically converted to another voltage level by an inductive action of the magnetic device. The converted voltage level is rectified by a diode or an active semiconductor device to produce the dc output voltage.
To produce a high level of power conversion efficiency, magnetic devices are often formed with windings wound in a single layer to reduce the proximity effect produced by high-frequency currents flowing in a proximate winding turn. The proximity effect causes high-frequency currents to flow predominantly in only a portion of a conductive winding, thereby increasing the effective resistance of the winding.
Magnetic devices are conventionally constructed with rectilinear core pieces such as “E” and “I” core pieces employed to form a high-frequency transformer or inductor. From practical manufacturing considerations, such designs require that a single-layer winding be formed on the vertical walls of the “E” portion of the magnetic core. Designs with such winding structures do not utilize the horizontal walls of the “E” or the “I” core pieces of the magnetic core, and accordingly introduce a high level of power losses.
Accordingly, what is needed in the art is a physical structure for a magnetic device and related method that provides a configuration to enable a wider distribution of winding turns to avoid the deficiencies in the prior art.